The present invention relates generally to draw punch cutters and more particularly to such cutters and their use for providing holes in panels to receive electrical components.
Mounting holes are currently provided in panels, such as electronic equipment chassis or front panels, by the commonplace drilling of circular mounting holes. When irregular or noncircular holes are desired in mass produced items, such holes are punched during the forming of the front panel or chassis, but in small scale production or equipment modification, the placement of such noncircular holes generally requires the drilling of several holes followed by hand sawing and filing to remove the desired material from the panel. Such a technique is clearly time-consuming and frequently results in an irregular, unsightly panel hole.
Draw punch cutters have been used to a limited extent in forming noncircular holes such as square holes and D-shaped holes which are circular save for one flat chordal surface as might be used for mounting toggle switches, potentiometers and the like. The holes which may be formed by these commercially available cutters are limited to those having a high degree of symmetry or regularity since such cutters employ a nut and bolt with the bolt shaft being slotted and with the mating punch and die having alignment keys which engage the bolt slot to maintain proper alignment between the punch and the die, and of course, the single bolt is merely tightened to achieve the cutting operation. Such known commercial draw punch cutters are not suitable for forming holes which are substantially elongated or which otherwise lack a high degree of symmetry since proper alignment, as well as uniformly distributed cutting pressures, are quite difficult to achieve.
A family of electrical connectors, referred to as "D sub-minatures", has recently become popular which require a panel opening of a generally trapezoidal shape having respective corner fillets and, depending upon the number of pins in the connector, of a substantially elongated configuration. With this type connector, either the receptacle or the plug may be mounted in the same hole configuration and, typically, a pair of mounting screws positioned adjacent the tapering edges of the trapezoid are employed. Mounting of such D sub-minature connectors in an existing panel has until now been by the drill, saw and file technique described above.